Method and apparatus for measuring performance times of a shutter apparatus
OwnerTracy Irelandinventor
Life of this patent
Estimating the term…
Abstract
A method and apparatus for measuring times for leading and trailing curtains of a camera shutter apparatus to traverse a focal plane aperture, an exposure time determined by the initial width between the two curtains, a photoflash delay time measured between the time the leading curtain begins the traverse and the time a photoflash apparatus is energized, and a change in exposure time between the beginning and the end of the traverse of the curtains. The invention may also measure certain bladed type shutter apparatus performance time characteristics. The invention involves a display means for displaying the times measured and a selection means for selecting among the various times measured for display.
Claims25
Apparatus for electrically measuring performance times of a camera shutter apparatus of the type having a leading curtain and a trailing curtain which are caused to traverse a focal plane aperture at different times for the usual purpose of exposing film when the shutter apparatus is operated, comprising:
- first measuring means for measuring an elapsed time for a leading curtain to traverse a focal plane aperture;
- second measuring means for measuring an elapsed time for a trailing curtain to traverse the focal plane aperture;
- third measuring means for measuring a time period between the time that the leading curtain starts the traverse of the focal plane aperture and the time that the trailing curtain starts the traverse of the focal plane aperture;
- and
- display means operative in conjunction with the first, second and third measuring means for displaying at least one of the times measured.
Apparatus for electrically measuring performance times of a shutter apparatus of a camera, comprising:
- first and second photoelectric sensor means for providing an electrical signal when exposed to light;
- means for providing a light communication path to the first photoelectric sensor means from a position relative to the shutter apparatus at which light will first pass through the shutter apparatus at the beginning of the exposure opening;
- means for providing a light communication path to the second photoelectric sensor means from a position relative to the shutter apparatus at which light will pass through the shutter apparatus at the beginning of the end of a full exposure opening;
- a clock means for providing clock pulses at a predetermined frequency;
- gating means, connected to the sensor means and the clock means, for conducting clock pulses in accordance with the electrical signals from the sensor means;
- counter means, connected to the gating means, for counting the clock pulses conducted by the gating means and for providing outputs indicative thereof;
- and
- display means, connected to the counter means, for displaying numbers indicative of the outputs supplied by the counter means.
A process for measuring the performance times of a shutter apparatus of a camera of the type having a leading curtain and a trailing curtain which are caused to traverse a focal plane aperture at different times for the usual purpose of exposing film when the shutter apparatus is operated, comprising:
- measuring an elapsed time for a leading curtain to traverse a focal plane aperture,
- measuring an elapsed time for a trailing curtain to traverse the focal plane aperture,
- measuring a first time period between the time that the leading curtain starts the traverse of the focal plane aperture and the time that the trailing curtain starts the traverse of the focal plane aperture, and
- displaying at least one of the times measured.
Dependencies are inferred from the claim text.